【新文速递】2024年4月7日固体力学SCI期刊最新文章

 

今日更新：International Journal of Solids and Structures 4 篇，Journal of the Mechanics and Physics of Solids 4 篇，Thin-Walled Structures 3 篇

International Journal of Solids and Structures

Symmetric unisolvent equations for linear elasticity purely in stresses

Adam Sky, Andreas Zilian

doi:10.1016/j.ijsolstr.2024.112808

纯应力线性弹性的对称非溶剂方程

In this work we introduce novel stress-only formulations of linear elasticity with special attention to their approximate solution using weighted residual methods. We present four sets of boundary value problems for a pure stress formulation of three-dimensional solids, and in two dimensions for plane stress and plane strain. The associated governing equations are derived by modifications and combinations of the Beltrami–Michell equations and the Navier-Cauchy equations. The corresponding variational forms of dimension d ∈ {2,3} allow to approximate the stress tensor directly, without any presupposed potential stress functions, and are shown to be well-posed in H1 ⊗ Sym(d) in the framework of functional analysis via the Lax–Milgram theorem, making their finite element implementation using C0-continuous elements straightforward. Further, in the finite element setting we provide a treatment for constant and piece-wise constant body forces via distributions. The operators and differential identities in this work are provided in modern tensor notation and rely on exact sequences, making the resulting equations and differential relations directly comprehensible. Finally, numerical benchmarks for convergence as well as spectral analysis are used to test the limits and identify viable use-cases of the equations.

在这项工作中，我们介绍了线性弹性的新型纯应力公式，并特别关注使用加权残差法对其进行近似求解。我们提出了四组边界值问题，分别针对三维固体的纯应力公式，以及平面应力和平面应变的二维公式。通过对 Beltrami-Michell 方程和 Navier-Cauchy 方程进行修正和组合，得出了相关的控制方程。相应的 d∈ {2,3}维度的变分形式允许直接近似应力张量，而无需任何预设的潜在应力函数，并通过 Lax-Milgram 定理证明了在函数分析框架内 H1 ⊗ Sym(d) 的良好假设，从而使其可以直接使用 C0 连续元素进行有限元实施。此外，在有限元设置中，我们通过分布对恒定和片断恒定体力进行了处理。这项工作中的算子和微分等式以现代张量符号提供，并依赖于精确序列，使得所产生的方程和微分关系可以直接理解。最后，利用收敛性数值基准和频谱分析来测试极限，并确定方程的可行用例。

Experimental-numerical analysis of silicon micro-scratching

S.O. Sperling, T. Bertens, J.P.M. Hoefnagels, K. van den Broek, M.G.D. Geers

doi:10.1016/j.ijsolstr.2024.112809

硅微划痕的实验-数值分析

The continuous decrease in feature size in the production of electronic chips has two major consequences for silicon wafers: (i) processing conditions for slicing and grinding operations need to be optimized and (ii) surface damage imposed by wafer handling and transport needs to be minimized. Cultivating a deeper understanding of the subsurface implications of contact, in particular during scratching, is necessary to achieve these goals. The active subsurface micro-deformation mechanisms, including phase transformations and crack formation, can only be measured post-scratch. On the other hand, numerical models are free of experimental constraints and can therefore serve an instrumental role in uncovering the active deformation mechanisms during scratching. However, model identification and validation with experimental data is essential for reliable simulation results. Therefore, in this paper, a numerical scratch model consisting of a continuum particle methodology combined with a large strain inelastic constitutive model is exploited, whereby the parameters are identified from indentation data. The numerical-experimental results are next compared for a range of micro-scratch tests. The experimental micro-scratch device was mounted inside a scanning electron microscope to perform in situ scratch experiments. The real-time observations at the scratched surface allowed to assess and exclude possible experimental artifacts. The simulations demonstrate the ability to investigate the evolution of the phase transformations underneath the scratched surface and relate this to the hydrostatic pressure. Notably, at the simulated subsurface phase boundary, hydrostatic tension was found which is expected to play an important role in median crack formation, as often reported in the literature. For the simulation and experiments, the steady state segments are compared and it was found that the model accurately reproduces the substantial surface recovery due to the Si-II  → Si-a phase transformation. Additionally, the simulated and experimental surface cross-sectional profiles for normal scratching loads of 30, 40 and 50 mN are in adequate agreement.

电子芯片生产中 特征尺寸的不断缩小对硅晶片产生了两大影响：(i) 需要优化切片和研磨操作的加工条件；(ii) 需要最大限度地减少晶片处理和运输造成的表面损伤。要实现这些目标，就必须深入了解接触的次表面影响，特别是在刮擦过程中。活跃的次表层微变形机制，包括相变和裂纹形成，只能在刮擦后进行测量。另一方面，数值模型不受实验限制，因此可在揭示划痕过程中的主动变形机制方面发挥重要作用。然而，要获得可靠的模拟结果，模型识别和实验数据验证至关重要。因此，本文采用了由连续粒子方法与大应变非弹性结构模型相结合的数值划痕模型，通过压痕数据确定参数。接下来比较了一系列微划痕试验的数值-实验结果。实验用微划痕装置安装在扫描电子显微镜内，以进行原位划痕实验。通过对划痕表面的实时观察，可以评估和排除可能存在的实验假象。模拟证明了研究划痕表面下相变演变的能力，并将其与静水压力联系起来。值得注意的是，在模拟的次表层相界处，发现了静水压力，正如文献中经常报道的那样，静水压力在中位裂纹的形成中起着重要作用。对模拟和实验的稳态段进行比较后发现，模型准确地再现了由于 Si-II → Si-a 相变引起的大量表面恢复。此外，在 30、40 和 50 mN 的正常划痕载荷下，模拟和实验的表面横截面轮廓也完全一致。

An analytical study on SMA beam-column actuators for anti-buckling problem

Alireza Ostadrahimi, Fathollah Taheri-Behrooz, Eunsoo Choi, Guoqiang Li

doi:10.1016/j.ijsolstr.2024.112792

针对抗屈曲问题的 SMA 梁柱推杆分析研究

The present paper focuses on studying the anti-buckling behavior of prismatic martensitic shape memory alloy (SMA) beam-columns. It combines analytical and semi-analytical approaches to investigate the process of column straightening for anti-buckling. We try to comprehensively describe this phenomenon and develop a mathematical model to formulate each step of the anti-buckling problem. Due to the complex stress–strain behavior of SMA material, nine different stages of stress-height diagrams may potentially occur during this effect; thus, for facilitating the design process of SMA structures, corresponding forces and moments to each stage, are analytically derived. Our demonstration establishes that the primary cause of beam-column straightening is not the uniformity of stress, but rather the achievement of uniform strain across all fibers of the cross-section. This uniform strain distribution implies that the curvature of the beam-column diminishes to zero.

本文重点研究棱柱马氏体形状记忆合金（SMA）梁柱的抗屈曲行为。它结合了分析和半分析方法来研究抗屈曲的柱矫直过程。我们试图全面描述这一现象，并建立一个数学模型来制定抗屈曲问题的每个步骤。由于 SMA 材料具有复杂的应力-应变行为，在这一过程中可能会出现九个不同阶段的应力-高度图；因此，为了方便 SMA 结构的设计过程，我们分析得出了每个阶段的相应力和力矩。我们的论证证明，梁柱矫直的主要原因不是应力的均匀性，而是横截面上所有纤维应变的均匀性。这种均匀的应变分布意味着梁柱的曲率会减小到零。

Experimental and numerical analysis of the buckling and postbuckling behavior of hyperelastic columns

Filipe Meirelles Fonseca, Paulo Batista Gonçalves

doi:10.1016/j.ijsolstr.2024.112813

超弹性柱屈曲和屈曲后行为的实验和数值分析

There has been an increasing amount of research and applications of hyperelastic bars, many of which involving beneficial buckling. However, there is limited information available regarding the stability of hyperelastic structural elements. Therefore, the objective of this study is to investigate experimentally and numerically the pre- and post-buckling behavior of hyperelastic columns until failure. Several constitutive models for hyperelastic incompressible materials undergoing finite deformations are tested. Uniaxial compressive and tensile tests are used to obtain the material constants and identify the most accurate model for the considered material (polyvinyl siloxane). Three-dimensional finite elements simulations are used for comparison. The experimental program is conducted considering different lengths and boundary conditions, covering a wide range of slenderness ratios. The use of a digital image correlation measurement software during the tests allows for an in-depth analysis of the deformation field. The Southwell method is adopted to evaluate the critical load and initial imperfection magnitude. The results are then compared with analytical critical loads and the influence of axial shortening, shear and self-weight is assessed. Results show that the nonlinear equilibrium path is also influenced by axial and shear deformations, self-weight, and anticlastic deformations, even under small strains. Different buckling mechanisms are identified, with some columns exhibiting limit-point instability. Finally, the results demonstrate that the hyperelastic columns can sustain high levels of deformation without damage, crucial in practical applications such as vibration control, energy absorption and harvesting, metamaterial development, bioengineering and medicine and flexible robotics, among others.

对超弹性杆件的研究和应用日益增多，其中许多涉及有益的屈曲。然而，有关超弹性结构元素稳定性的信息却十分有限。因此，本研究的目的是通过实验和数值方法研究超弹性柱在屈曲前和屈曲后直至破坏的行为。本研究测试了几种发生有限变形的超弹性不可压缩材料的构成模型。通过单轴压缩和拉伸试验获得了材料常数，并为所考虑的材料（聚乙烯硅氧烷）确定了最准确的模型。三维有限元模拟用于比较。实验程序考虑了不同的长度和边界条件，涵盖了广泛的细长比范围。在试验过程中使用数字图像相关测量软件可对变形场进行深入分析。采用 Southwell 方法来评估临界载荷和初始缺陷大小。然后将结果与分析临界载荷进行比较，并评估轴向缩短、剪切和自重的影响。结果表明，即使在小应变下，非线性平衡路径也会受到轴向和剪切变形、自重和反弹性变形的影响。还发现了不同的屈曲机制，一些柱子表现出极限点不稳定性。最后，研究结果表明，超弹性柱可以承受高水平的变形而不会损坏，这在振动控制、能量吸收和收集、超材料开发、生物工程和医学以及柔性机器人等实际应用中至关重要。

Journal of the Mechanics and Physics of Solids

Modeling shortest paths in polymeric networks using spatial branching processes

Zhenyuan Zhang, Shaswat Mohanty, Jose Blanchet, Wei Cai

doi:10.1016/j.jmps.2024.105636

利用空间分支过程模拟聚合物网络中的最短路径

Recent studies have established a connection between the macroscopic mechanical response of polymeric materials and the statistics of the shortest path (SP) length between distant nodes in the polymer network. Since these statistics can be costly to compute and difficult to study theoretically, we introduce a branching random walk (BRW) model to describe the SP statistics from the coarse-grained molecular dynamics (CGMD) simulations of polymer networks. We postulate that the first passage time (FPT) of the BRW to a given termination site can be used to approximate the statistics of the SP between distant nodes in the polymer network. We develop a theoretical framework for studying the FPT of spatial branching processes and obtain an analytical expression for estimating the FPT distribution as a function of the cross-link density. We demonstrate by extensive numerical calculations that the distribution of the FPT of the BRW model agrees well with the SP distribution from the CGMD simulations. The theoretical estimate and the corresponding numerical implementations of BRW provide an efficient way of approximating the SP distribution in a polymer network. Our results have the physical meaning that by accounting for the realistic topology of polymer networks, extensive bond-breaking is expected to occur at a much smaller stretch than that expected from idealized models assuming periodic network structures. Our work presents the first analysis of polymer networks as a BRW and sets the framework for developing a generalizable spatial branching model for studying the macroscopic evolution of polymeric systems.

最近的研究发现，聚合物材料的宏观机械响应与聚合物网络中远节点之间的最短路径（SP）长度统计之间存在联系。由于这些统计量的计算成本很高，而且难以从理论上进行研究，因此我们引入了分支随机游走（BRW）模型来描述聚合物网络粗粒度分子动力学（CGMD）模拟中的最短路径统计量。我们推测，BRW 到达给定终止位点的首次通过时间（FPT）可用于近似聚合物网络中远节点之间的 SP 统计量。我们为研究空间分支过程的 FPT 搭建了一个理论框架，并获得了一个分析表达式，用于估算作为交联密度函数的 FPT 分布。我们通过大量数值计算证明，BRW 模型的 FPT 分布与 CGMD 模拟的 SP 分布非常吻合。BRW 的理论估计和相应的数值实现为近似聚合物网络中的 SP 分布提供了一种有效的方法。我们的研究结果具有物理意义，即通过考虑聚合物网络的现实拓扑结构，广泛的键断裂预计会发生在比假设周期性网络结构的理想化模型小得多的伸展范围内。我们的研究首次将聚合物网络作为 BRW 进行分析，并为研究聚合物系统的宏观演化建立了一个可推广的空间分支模型框架。

A machine learning interatomic potential for high entropy alloys

Lianping Wu, Teng Li

doi:10.1016/j.jmps.2024.105639

高熵合金的机器学习原子间势能

High entropy alloys (HEAs) possess a vast compositional space, providing exciting prospects for tailoring material properties yet also presenting challenges in their rational design. Efficiently achieving a well-designed HEA often necessitates the aid of atomistic simulations, which rely on the availability of high-quality interatomic potentials. However, such potentials for most HEA systems are missing due to the complex interatomic interaction. To fundamentally resolve the challenge of the rational design of HEAs, we propose a strategy to build a machine learning (ML) interatomic potential for HEAs and demonstrate this strategy using CrFeCoNiPd as a model material. The fully trained ML model can achieve remarkable prediction precision (>0.92 R2) for atomic forces, comparable to the ab initio molecular dynamics (AIMD) simulations. To further validate the accuracy of the ML model, we implement the ML potential for CrFeCoNiPd in parallel molecular dynamics (MD) code. The MD simulations can predict the lattice constant (1% error) and stacking fault energy (10% error) of CrFeCoNiPd HEAs with high accuracy compared to experimental results. Through systematic MD simulations, for the first time, we reveal the atomic-scale deformation mechanisms associated with the stacking fault formation and dislocation cross-slips in CrFeCoNiPd HEAs under uniaxial compression, which are consistent with experimental observations. This study can help elucidate the underlying deformation mechanisms that govern the exceptional performance of CrFeCoNiPd HEAs. The strategy to establish ML interatomic potentials could accelerate the rational design of new HEAs with desirable properties.

高熵合金（HEAs）拥有广阔的成分空间，为定制材料特性提供了令人兴奋的前景，但同时也为其合理设计带来了挑战。要有效实现精心设计的高熵合金，往往需要原子模拟的帮助，而原子模拟依赖于高质量的原子间势能。然而，由于原子间相互作用的复杂性，大多数 HEA 系统都缺少这种势能。为了从根本上解决 HEA 合理设计所面临的挑战，我们提出了一种为 HEA 建立机器学习（ML）原子间势的策略，并以 CrFeCoNiPd 为模型材料演示了这一策略。训练有素的 ML 模型可实现显著的原子力预测精度（>0.92 R2），与原子分子动力学（AIMD）模拟相当。为了进一步验证 ML 模型的准确性，我们在并行分子动力学（MD）代码中实现了 CrFeCoNiPd 的 ML 势。与实验结果相比，MD 模拟能高精度地预测 CrFeCoNiPd HEAs 的晶格常数（误差为 1%）和堆积断层能（误差为 10%）。通过系统的 MD 模拟，我们首次揭示了 CrFeCoNiPd HEAs 在单轴压缩条件下与堆积断层形成和位错交叉滑移相关的原子尺度形变机制，这与实验观察结果是一致的。这项研究有助于阐明决定铬铁钴镍钯高压电子元件优异性能的基本变形机制。建立 ML 原子间电位的策略可加速具有理想性能的新型 HEAs 的合理设计。

Multiscale modeling of dislocation-mediated plasticity of refractory high entropy alloys

Feng Zhao, Wenbin Liu, Xin Yi, Yin Zhang, Huiling Duan

doi:10.1016/j.jmps.2024.105640

难熔高熵合金位错介导塑性的多尺度建模

Refractory high entropy alloys (RHEAs) have drawn growing attention due to their remarkable strength retention at high temperatures. Understanding dislocation mobility is vital for optimizing high-temperature properties and ambient temperature ductility of RHEAs. Nevertheless, fundamental questions persist regarding the variability of dislocation motion in the rugged energy landscape and the effective activation barrier for specific mechanisms, such as kink-pair nucleation and kink migration. Here we perform systematic atomistic simulations and conduct statistical analysis to obtain the effective activation barriers for the mechanisms underlying various types of dislocation motion in a typical RHEA, NbMoTaW. Moreover, a stochastic line tension model is developed to calculate the activation barrier with substantially reduced computational costs. By incorporating the effective activation barriers into the crystal plasticity model, a multiscale simulation framework for predicting the mechanical properties of RHEAs is established. The ambient temperature yield strength of NbMoTaW is well-predicted by the kink-pair nucleation mechanism of screw dislocations, while the strengthening originating from screw dislocations does not predominate at high temperatures. Our work provides a robust foundation for atomistic studies of effective dislocation behaviors in random solution solids, elucidating the intricate relationship between microscopic mechanisms and macroscopic properties.

难熔高熵合金（RHEAs）因其在高温下的显著强度保持性而日益受到关注。了解位错运动对于优化 RHEA 的高温特性和环境温度延展性至关重要。尽管如此，关于位错运动在崎岖能谱中的可变性以及特定机制（如扭结对成核和扭结迁移）的有效活化势垒等基本问题依然存在。在此，我们进行了系统的原子模拟，并进行了统计分析，以获得典型的 RHEA（NbMoTaW）中各种差排运动机制的有效活化能垒。此外，我们还开发了一种随机线拉伸模型，用于计算活化势垒，大大降低了计算成本。通过将有效活化势垒纳入晶体塑性模型，建立了预测 RHEA 力学性能的多尺度模拟框架。铌钼钽钨的常温屈服强度可以很好地通过螺位错的晶对成核机制进行预测，而螺位错产生的强化在高温下并不占主导地位。我们的工作为无规溶液固体中有效位错行为的原子研究奠定了坚实的基础，阐明了微观机制与宏观特性之间错综复杂的关系。

Molecular Simulation-guided and Physics-informed Constitutive Modeling of Highly Stretchable Hydrogels with Dynamic Ionic Bonds

Hua Yang, Danming Zhong, Ping Rao, Shaoxing Qu

doi:10.1016/j.jmps.2024.105641

具有动态离子键的高弹性水凝胶的分子模拟指导和物理信息成分建模

Adaptive polymers are being designed with dynamic molecular bonds or chain interactions to respond with external stimuli with unparalleled mechanical properties and multifunctionality. An elegant example is to substantially enhance the stretchability and toughness of hydrogels through the use of ionic bond interactions. To assist the materials design and applications, a predictive theory is in high demand. However, existing multi-scale mechanics models often rely on empirical assumptions and relationships derived from polymer chemistry or physics to describe the evolution of microscale details under external stimuli, which are challenging to be validated experimentally. This study introduces a new methodology to develop constitutive theories for stretchable hydrogels based on insights garnered from molecular dynamics (MD) simulations. The continuum-level viscoelastic theory establishes the thermodynamics framework for stress-strain relationships, while MD simulations inform the evolution mechanisms of microscale bond interactions and network rearrangements, such as the bond distance and network relaxation time. These insights are then properly formulated based on polymer physics principles and fed into the continuum-level model. The resulting constitutive theory closely captures the stress responses at various loading conditions observed in experiments, as well as the microscale system volume and bond distance uncovered in MD simulations. Parametric studies are conducted to investigate the influences of various loading and material parameters on the mechanical properties of the materials, including loading rates, network crosslinking density, maximum strain, and bonding strength. Overall, the study establishes the connection between microscale network structure and mechanical responses of stretchable hydrogels with dynamic ionic bonds. It also offers practical guidance for optimizing material structures and loading conditions to enhance energy absorption and dissipation capabilities. The modeling approach can be extended to the study of other adaptive polymers with different dynamic bonds to create more precise and physically meaningful constitutive models.

人们正在设计具有动态分子键或链相互作用的自适应聚合物，以对外部刺 激做出反应，从而获得无与伦比的机械性能和多功能性。利用离子键相互作用大幅提高水凝胶的拉伸性和韧性就是一个很好的例子。为了帮助材料设计和应用，对预测理论的需求很高。然而，现有的多尺度力学模型通常依赖于从聚合物化学或物理学中得出的经验性假设和关系来描述微尺度细节在外部刺 激下的演变，而这些假设和关系很难通过实验进行验证。本研究介绍了一种新方法，基于分子动力学（MD）模拟获得的洞察力，开发可拉伸水凝胶的构成理论。连续级粘弹性理论为应力-应变关系建立了热力学框架，而 MD 模拟则为微观键相互作用和网络重排（如键距和网络弛豫时间）的演变机制提供了信息。然后，根据聚合物物理学原理对这些见解进行适当表述，并将其输入连续级模型。由此产生的构成理论密切捕捉了实验中观察到的各种加载条件下的应力反应，以及 MD 模拟中发现的微观系统体积和键距。研究还进行了参数研究，以探讨各种加载和材料参数对材料力学性能的影响，包括加载速率、网络交联密度、最大应变和结合强度。总之，该研究建立了具有动态离子键的可拉伸水凝胶的微尺度网络结构与机械响应之间的联系。它还为优化材料结构和加载条件以增强能量吸收和耗散能力提供了实用指导。该建模方法可扩展到其他具有不同动态键的自适应聚合物的研究中，以创建更精确、更有物理意义的构成模型。

Thin-Walled Structures

A methodological approach towards modelling Steel/CF hybrid damage behaviour under bending

Xinyu Hu, Peng Zhang, Claudia Creighton, Bin Zhu, Wang Liu, Richard Taube, Matthias Weiss

doi:10.1016/j.tws.2024.111860

模拟弯曲下钢材/纤维素混合材料损伤行为的方法论

This study presents a combined experimental-numerical approach to predict the load-displacement response of a steel/carbon fibre composite in bending-dominated forming. The 3D material and damage model consider the residual strength of kinked fibres through a deviation-based calibration method. For the first time, a special pure bending test that allows controlled forming to specific curvatures is combined with in situ damage analysis to test and calibrate a damage model for hybrid material forming. The results of this study show that the mechanical performance and damage mode in bending depends on the carbon fibre layup orientation and that the model accurately reproduces the load-bearing capacity, the load drop at fibre kinking and the mechanical behaviour post-forming induced damage.

本研究提出了一种实验与数值相结合的方法，用于预测钢/碳纤维复合材料在以弯曲为主的成形过程中的载荷-位移响应。三维材料和损伤模型通过基于偏差的校准方法考虑了扭结纤维的残余强度。这是首次将可控制特定曲率成形的特殊纯弯曲试验与原位损伤分析相结合，以测试和校准混合材料成形的损伤模型。研究结果表明，弯曲时的机械性能和损伤模式取决于碳纤维的铺层取向，模型准确再现了承载能力、纤维扭结时的载荷下降以及成形后诱发损伤的机械性能。

Primary resonance analysis of hyperelastic doubly curved shallow shells subjected to external loading

Habib Allah Mazinanian, Habib Ahmadi, Kamran Foroutan

doi:10.1016/j.tws.2024.111867

受外部荷载作用的超弹性双曲浅壳的初级共振分析

In this paper, primary resonance analysis of stiffened shallow shells with doubly curved ones is evaluated employing an analytical method. The shell material is hyperelastic, and the system is under external loading. The shell's mathematical model is developed using the first-order shear deformation theory (FSDT), considering von-Kármán's non-linear shell assumptions, multiple scales, and the Galerkin method. The Neo-Hookean hyperelastic type has been selected to explain the non-linear elasticity of the material. The stiffened shell geometric can be changed to different forms such as hyperbolic, cylindrical, and spherical shells by curvature components set. Several material parameters, number of stiffeners, geometrical ratio, etc., that affect shell oscillations results are examined and investigated in detail. According to the numerical results, it is characterized by increasing and decreasing the stiffener's number, damping coefficients (µ), and force amplitude (K), leading to significant changes in fundamental frequencies of the stiffened doubly curved shallow shell. Also, increasing of parameter σ, causes to increase the peak of response amplitude.

本文采用一种分析方法，对双曲面加劲浅壳的主共振分析进行了评估。壳体材料为超弹性材料，系统承受外部载荷。考虑到 von-Kármán 的非线性壳假设、多尺度和 Galerkin 方法，使用一阶剪切变形理论 (FSDT) 建立了壳的数学模型。选择了新胡克超弹性类型来解释材料的非线性弹性。通过曲率分量的设置，加劲壳的几何形状可以变为不同的形式，如双曲壳、圆柱壳和球壳。对影响壳体振荡结果的几个材料参数、加劲件数量、几何比例等进行了详细的检查和研究。数值结果表明，加劲件数量、阻尼系数 (µ) 和力振幅 (K) 的增减会导致加劲双曲浅壳的基频发生显著变化。此外，参数 σ 的增加也会导致响应振幅峰值的增加。

Prediction of burst pressure of corroded thin-walled pipeline elbows subjected to internal pressure

Changqing Gong, Shihua Guo, Rui Zhang, Dan M. Frangopol

doi:10.1016/j.tws.2024.111861

受内压腐蚀的薄壁管道弯头的爆破压力预测

The thinning of pipeline walls, resulting from corrosion, reduces their capacity to withstand internal pressures. Accurate prediction of the remaining strength of corroded pipelines is important to prioritize mitigation efforts for critical defects. While burst pressure models for straight pipelines have been well established, the research on the burst capacity of pipeline elbows is still limited, and most studies were established on rectangular-shaped corrosion. This study focuses on developing a new model for assessing the burst capacity of elbows containing single semi-elliptical corrosion, based on extensive three-dimensional elastic-plastic finite element (FE) analysis validated by full-scale burst tests of straight and elbow pipelines. The Pipe CORRosion Criterion (PCORRC) method, originally developed for straight pipelines, was re-calibrated to predict the remaining strength of corroded pipeline elbows. A revised factor was introduced to account for hoop stress variations caused by elbow curvatures. Results indicate that the revised model offers observable accuracy improvement over the existing models reported in the literature. The proposed model will improve the integrity management of corroded elbows.

腐蚀导致管道壁变薄，降低了其承受内部压力的能力。准确预测腐蚀管道的剩余强度对于优先缓解关键缺陷非常重要。虽然直管道的爆破压力模型已经非常成熟，但对管道弯头爆破能力的研究仍然有限，而且大多数研究都是针对矩形腐蚀建立的。本研究基于广泛的三维弹塑性有限元（FE）分析，并通过直管和弯头管道的全尺寸爆破试验进行验证，重点开发了一种新模型，用于评估含有单个半椭圆形腐蚀的弯头的爆破能力。最初针对直管道开发的管道 CORRosion 标准 (PCORRC) 方法经过重新校准，可用于预测腐蚀管道弯头的剩余强度。引入了一个修订系数，以考虑弯头曲率引起的箍应力变化。结果表明，与文献中报道的现有模型相比，修订后的模型具有明显的精度改进。建议的模型将改善腐蚀弯头的完整性管理。